ammarolli

I went to LBS with my bike and they adjusted my bike and everything.

Now it's weekend I really wanted to ride my bike but the workshop opens again on monday.

Went back few times to get my front derailleur sorted out unfortunately I was stupid and forgot to check the alignment in small chainring in the front.

Now I got a new problem which didn't exist before the front derailleur is not moving when I trimmed it on the small ring.

I see that when I use the trim that cable get slack but the derailleur is not moving.

Anyone know what could be causing that?

ecnewell 

Did you check the "L" limit screw? If it was screwed in during their adjustment, it would cause the symptom you're describing.

(Note: not a mechanic, but read your question and have done exactly this myself before.)

ammarolli

It was all working 100% well before I went with the bike to LBS so I don't think the limit screw is causing that.

I think my STI shifter is missing a click and therefore the trim is not working.

jimincalif

The trim doesn't work right unless the cable tension and limit screws are just so. If it is too loose, then when you downshift the derailleur goes all the way to the limit screw and there is nothing left for trim. I'd guess it is either the limit screw should be backed off or the cable tightened slightly.

I had to spend some time with it when I installed a new derailleur last year. Took me a few minutes of experimentation to start understanding the relationship between the limit screws, cable tension and the trim click in the shifter. Once I figured out how it all worked I was able to get it dialed in. I set the limit screws to avoid inside chain rub in low gear and outside chain rub in high gear. Once these were set it was pretty much a matter of tweaking the cable tension to get the derailleur to reach both limit screw settings and have the trim work on both rings.

maddog34

find a better bike shop... they left the cable too loose.... and there are probably other issues too... sounds like the mechanic got in a hurry, and didn't do the tune up correctly.... or he/she is not a very good mechanic.

if the cable housings were replaced, an endcap might have settled, too... once again, the mechanic was not careful.

tighten up the cable by loosening the pinch bolt, then pulling it tight... i PRE-TENSION shift cables by turning the limit screw in a full turn, then do the pull cable/tighten nut or bolt... then reset the limit screw to it's correct position...

pdlamb

Does the FD shift to a smaller chainring? Something may be gummed up in either the cable or the derailer that keeps it from moving. Or a cable might have been kinked.


If it's a decent shop, take it back to them and they'll figure it out and fix it pronto. Try not to rub their noses in it, everybody makes misteaks.

ammarolli

It's the Trek Dealer where I live and they have fine mechanic there.

I went back to the shop after testing the derailleur cause I thought I heard the chain rubbing in the highest gears.

Then the manager did adjust the derailleur but did not check if the gears on the other side of the front mech.

I'm going to see if there is someone there tomorrow that could fix my bike.

However I loosened the cable from the derailleur and that made no difference to the rub.

It's rubbing in almost all gears in the small ring except maybe smallest 1-3 cogs in the back.

02Giant 

They have a "fine mechanic" but it takes multiple trips to make a simple adjustment. I think your process for assessing the mechanics abilities is flawed.

ammarolli

No maybe there is something wrong with me no the the bike however I went there today and they wear surprisingly open.

The manager looked at my bike and told me that is the cable tension is off and I need new inline barrel adjuster to correct this problem.

He told me that the bike was not like that yesterday but however I noticed this when I came home so.

They don't have the barrel adjuster in stock at the moment and he thinks that going to solve the problem so I need to wait until they get the shipment early next week hopefully.

CliffordK

So, what exactly are your symptoms?

Can you shift into the small front sprocket? Is that a double or triple?

Does the chain rub on the inside of the derailleur when shifted to the small front and large rear? In that case, if the cable is slack, then it is a lower limit screw adjustment (or you are beyond the range of the derailleur).

I'm surprised the shop doesn't have barrel adjusters in stock. But, you should be able to adjust the cable tension without one, it just takes a little more effort.

revcp 

but I don't see that you listed brand and model of your FD. Type of FD could offer a solution to the problem.

ammarolli

It's the new 10speed shimano tiagra 4700 front derailleur 50/32 - double chainrings.

The symptoms are that the derailleur shifts fine to the big and small chainrings. However the derailleur doesn't move far enough so the chain rubs on the derailleur cage in gears 1-7 on the small ring.

So the when I'm shifting the derailleur down to small ring I have one extra click in the shifter and when I the click the cable get looser but It doesn't move the derailleur.

fietsbob

STI left/front, shifters don't really fine tune like friction shifters can..

ammarolli

What do you mean?

ecnewell 

Combination of cable tension and limit screw depth makes the most sense. If you're not missing shifts, I doubt it's the STI.

Shift to the small chainring--where you're getting this rubbing symptom--and get under/beside the derailleur so you have a good line of sight on the limit screws. Is the tip of the L screw up against the tab? If so, you're bottomed out, and it makes sense that the trim is doing nothing. My hunch is it needs to be backed out. You may also need a little more cable tension once you've done this.

Eggman84

Sounds to me like the low (L) limit screw is not adjusted properly. You said that at one point everything was working properly other than the chain was rubbing when you were in the large chainring and smallest cogs combination. Then you took it to the LBS. I suspect the mechanic meant to adjust the high (H) limit screw to allow the front derailleur to move further out slightly (to stop the rub). The may also have adjusted the low limit screw where the front derailleur does not move far enough inboard (toward the frame). You should not have cable slack when in the smallest chainring. I suggest that with the chain on the small chainring and the largest cog, turn the low limit screw counterclockwise until the inner art of the cage is not hitting the chain. After this test your shifting in all combinations. If you turn the low limit screw out to much, the only problem could be the chain over shifting and coming off the small chainring as you downshift. In this case, you need to screw the low limit screw in slightly.

Good luck.

fietsbob

STI Does Not really Trim..

They go Ka thunk throwing the chain sideways ,, quick shifts rely on those ramps and pins and modified teeth..

cage is oddly shaped to not drag unless you go past the intention, into cross-chain territory...

Not a fan of engineers taking skills out of cycling, but they simplify to increase rider-sales..



....

ammarolli

I think the sti shifter is missing a click like I'm getting only half of the click but full click.

The reason why I think the sti shifter is missing a click is the fact I rode the bike in the morning to LBS and chain was not rubbing against the fd like it's doing now.

I'm not a expert so I don't know.

LBS is going to go over the shifter once they get new barrel adjuster shipped.

I'm going to talk to them on thursday and see if they got the adjuster.

I'm not going to do anything more to the shifter.. just going to leave it to LBS.

SylvainG

Doing just half a click also points to the derailleur bottoming on its Low Gear Limit Stop screw.

ammarolli

Thanks for the info.

You might have the solution. I'm going to ask about that when LBS is ready to fix this problem.

maddog34

Tiagra 4700 left shifters have 5 clicks for my 2x10 setup, and a triple would have two more clicks...... there is no fine adjustment in the lever, and an inline fine adjustment is needed to fine tune the shifting... my frame that has this group on it has an adjuster on the frame of the bike... some bikes don't have those on the frame...

let them install the adjuster, then make certain they ALIGN the derailleur correctly to the chain rings, because if that alignment is off even a small fraction, there WILL be rubbing, since the 4700 is a 10 sp. setup, and they are quite closely fit to the chain. And all those gears in the back makes for quite a bit of chain bend when cross-chaining(big front/big back, or small front/small back gears). The Front Der. ALIGNMENT must be nearly PERFECT... perfection is a concept, not a reality.... mine made noise when i first installed it... noise went away once i had that front der. aligned better... it was FINICKY to tune, too!

one more thing to look at... the Der. is tunable for different cable routings! there is a small item at the cable pinch bolt that is swappable to one of two positions, and a tuning guide is included with the new derailleurs... follow the instructions included with the der./group for proper orientation of the cable... you can find the instructions online too...

revcp 

To get the required cable tension with that long arm on the fd it's necessary to adjust the low limit screw so that it's pushing the cage over the big ring. The cable is then really tightened and a little set screw that pushes against the seat tube is adjusted to swing the rear of the cage out a millimeter or two from square. After that the the low limit screw is adjusted so it shifts into the smaller ring without throwing it off to the inside. It's my guess the LBS improperly adjusted the low limit screw or has the cage at the wrong angle.

ammarolli

Thanks for the info.

I'm not an expert but I think my left shifter only has 4 clicks so I'll mention that when lbs is ready to adjust the shifter.

southpier

for what it's worth, I had a similar problem last year. after riding about 3 times, the front derailleur lever did nothing. the cable had worn through the housing at the outside of the bend and bare wire was exposed (bar end shifter).

maddog34

ok... umm, there are 5 POSITIONS in the detents... with 4 four CLICKS... shoulda typed that in differently, i guess... ......
off to the races for me today... Super-D event...